A known display system has indicia which is readable in bright sunlight when a light source within the display system is energized. However, when the light source in the display system is not energized, the indicia is not readable, even in bright sunlight.
This known display system includes a prism having a pair of light receiving faces disposed in planes which intersect at an apex. When a light source is energized, light is transmitted to the light receiving faces of the prism. The light is transmitted through the prism from the light receiving faces to a light emitting face of the prism. The light emitting face of the prism has a series of parallel V-shaped grooves. The V-shaped grooves have side surfaces which disperse rays of light transmitted from the light receiving faces of the prism to the light emitting face of the prism.
A display panel is disposed in front of the light emitting face of the prism. Indicia on the display panel is exposed to light transmitted from the light emitting face of the prism. This indicia is observable when the source of light is energized, even when the display panel is exposed to bright sunlight. However, the indicia on the display panel is obscured when the source of light is not energized. This known display system is disclosed in U.S. Pat. No. 5,295,050 issued Mar. 15, 1994 and entitled "Display System".